Mandrel bar steadier for seamless-tube mills



Aug. 11, 1970 SANDERSON I 3,523,440

MANDREL BAR STEADIER FOR SEAMLESS-TUBEMILLS Filed July 26, 1967 INVENTOR GUN/VAR SA/VDERSON 5 By g 7 5 ////fl Ammey United States Patent 3,523,440 MANDREL BAR STEADIER FOR SEAMLESS-TUBE MILLS Gunnar Sanderson, McKeesport, Pa., assignor to United States Steel Corporation, a corporation of Delaware Filed July 26, 1967, Ser. No. 656,253 Int. Cl. B21b 39/20 US. Cl. 72-250 3 Claims ABSTRACT OF THE DISCLOSURE In a steadier, a base and standard thereon support a rotatable shaft over the axial path of a mandrel bar or tube thereon. A crank on the shaft mounts a steadier head, the latter rotatable in and out of an operative position whereby it confines a bar or tube. The latter may also be confined by the steadier head and guide means therebelow. One or more guide means may be spaced on opposite sides of the base along the axial path. Size changes are provided by yoke-shaped blocks removably disposed in the steadier head.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a bar steadier for a seamlesstube mill and the like, wherein a rotating mandrel bar is steadied before the pierced shell or tube emerges from the mill, as well as for steadying the emerging tube with the bar therein. More particularly, it relates to a structure substantially completely confining a bar, thus making it impossible for a rotating bar to whip free of the steadier and difficult for a bar to bend excessively when the tremendous horizontal and rotational forces are exerted on the bar during piercing.

Description of the prior art Seamless-tube mills of known types include a long and relatively slender mandrel bar. Opposed rolls force a billet or shell over the mandrel or plug carried thereon. A bar steadier is an arrangement for steadying the rotating bar before the pierced shell or tube emerges from the mill, for guiding and steadying the tube with the mandrel bar therein and for opening to permit the tube to be kicked out after bar removal therefrom. For a more complete description of such mills and steadiers, reference can be made to US. Pats. Nos. 1,950,929 and 2,306,827.

In some prior art steadiers, a plurality of guide rolls may pivot on horizontal shafts, spaced circumferentially of the axial bath path. In other steadiers, two co-operating blocks may pivot on vertical shafts. In either arrangement, one or more motors or hydraulic motors operate racks and pinions or other linkages to turn the steadier means toward and away from the axial path of the bar. Where the internal diameter of the surrounding steadier means, for example, mustbe made considerably larger than the bar to accommodate the tube, the rotating bar may flex eccentrically under load and force apart the confining rolls or blocks. Should the flexing or Whipping continue, the bar may leave the steadier through this opening, usually resulting in bar failure and downtime on the mill. Scale is usually present on a hot tube and drops therefrom on the racks and pinions or other linkages therebelow. This increases maintenance costs. Between maintenance periods, scale-clogged pinions may prevent complete closure of the steadier means, thus leading to possible bar failure.

SUMMARY OF THE INVEN'IllON The improved steadier has an L-shaped frame, the vertical portion being a standard supported on a base. The

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horizontal portion extends under the path of the bar. This horizontal portion is generally U-shaped to receive a steadier head above the path and to confine a bar from above and below. A bearing having a horizontal axis is supported on the standard and journals a shaft extending over the path. A crank on the shaft end supports a steadier head on its opposite end, perpendicular to the axis of the bar. A crank or lever mounted on the opposite end of the shaft is pivotally connected to and rotatable by a hydraulic motor, pivotally supported on the base. Hydraulic motor actuation serves to rotate the steadier head into operating or non-operating positions with respect to the workpiece. The steadier head preferably includes a housing and a yoke-shaped block removably disposed therein and adapted to confine a tube from above and on both sides. Hence, co-operation of head and base provides substantially complete confinement for the Workpiece. Usually, open or closable guide means for the workpiece are spaced along the axial path thereof. Hence, a steadier head and adjacent guide means may also cooperate to confine a workpiece.

The advantages of the improvement over the prior art include:

(1) The steadier provides substantially complete confinement for a bar, thus making it impossible for the bar to whip free of the steadier. Additionally, the yoke-shaped block, while permitting free movement of a tube, effectively limits the eccentric orbit of bar rotation, hence making it difficult for a bar to bend or flex excessively. Such effective confinement is assured further by suspension of the steadier head perpendicular to the bar axis.

(2) Overhead suspension of the steadier head and spaced actuating means therefor has eliminated any problems incident to the collection of falling scale.

(3) The yoke-shaped block permits rapid size changes.

BRIEF DESCRIPTION OF THE DRAWINGS A complete understand if the invention may be obtained from the following detailed description and explanation which refers to the accompanying drawings illustrating the present preferred embodiments. In the drawings:

FIG. 1 is a plan view of a portion of a seamless-tube mill outlet table, with the steadier apparatus shown in operating position;

FIG. 2 is an enlarged vertical section, taken on line IIII of FIG. 1;

FIG. 3 is a vertical side elevation of FIG. 2, with parts broken away, also showing the steadier head in chain lines in non-operating position; and

FIG. 4 is an enlarged portion of FIG. 3 partly in section, showing the yoke-shaped block in the steadier head.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to the drawings, FIG. 1 shows a portion of an outlet table 10 of a seamless-tube mill, supported on spaced beams 11. A rotating mandrel bar 12 is adapted to support a tube or shell 13 as it emerges from the mill and follows an axial path. After bar 12 is withdrawn from tube 13, kickout means 14 are actuated to discharge a tube transversely of table 10. Spaced guide means on table 10 may also serve to guide and to support a bar or tube. In one embodiment a cradle 15, mounted on beams 11, supports a trough or guide 16. An open, arcuate-shaped, side 17 of the guide faces upwardly and is spaced below the axial path of bar 12. In a second embodiment, a cradle 18, mounted on beams 11, supports a guide 19, shaped and spaced substantially the same as guide 16. A cover means 20 for guide 19 is pivoted on a shaft 21 into and out of covering position by a hydraulic cylinder 22. The described cover means assists in guiding but is not adapted to confine a whipping bar. For clarity,

in FIG. 2, this embodiment is shown only as a portion of guide 19. The mill and parts thereof as described above are not otherwise shown, since they may be of any standard construction and mode of operation, for example, as shown in the aforementioned U.S. Pat. Nos. 1,950,929 and 2,306,827.

My steadier 23 is shown as spaced between guides 16 and 19. Mounted on beams 11 and fastened thereto by bolts 24, steadier 23 comprises an L-shaped frame, including a U-shaped base 25 and a standard 26 mounted thereon. A bearing 27 having a horizontal axis is supported on standard 26. As illustrated, base 25, standard 26 and bearing 27 comprise an integral structure. Bearing 27 journals a shaft 28, the respective ends 29, 30 thereof preferably having square cross sections. A crank 31, has a square cross-sectioned upper end 32 with a square opening 33 therein adapted to receive end 30 of shaft 28. Crank 31 is mounted on and suspended from shaft 28 perpendicular to the axial path of bar 12, being held against a shoulder 34 on shaft 28 by bolts 35.

A steadier head 36 adapted to confine bar 12 or tube 13 comprises the opposite or lower end of crank 31. Steadier head 36 includes a yoke-shaped housing or socket 37 adapted to receive a yoke-shaped block or insert 38 therein. Block 38 is held loosely against a yoke-shaped retaining flange 39 in housing 37 by four bolts 40, held in position in housing 37 by cotter pins 41. An opening 42 in flange 39 is shaped large enough to accommodate a size range of blocks 38. A corresponding opening in any individual block 38 comprises spaced parallel sides 43 connected by a semi-circular upper portion 44. The respective dimensions thereof are such, preferably, to confine closely a tube 13, thereby providing only a limited space from above and on both sides wherein a bar may rotate eccentrically. Substantially complete confinement of a bar or tube will then be afforded by a surface 45 of base 25 or as illustrated in the drawings by guides 16 and 19, when they are spaced closely adjacent the steadier. In addition to a bottom surface 45, the U-shaped portion of base 25 includes vertical sides 46, to which wear plates 47 may be fastened by spaced bolts 48. It is evident that the relatively massive crank 31 suspended perpendicularly to the bar or tube axis and having the steadier head 36 thereof extending deeply into the U-shaped portion of base 25 assure substantially complete confinement of a bar 12.

A crank or lever 49 has square opening 50 therein adapted to receive end 29 of shaft 28. Lever 49 is keyed to shaft 28 by a key (not shown). Lever 49 has a bifurcated lower end 51 adapted to receive a piston 52 of a hydraulic moter 53. A pin 54 holds piston 52 in pivotal relationship in forked end 51. A pin 55 pivotally attaches a clevis 56 on the bottom of motor 53 to a bracket 57, mounted by means of spaced bolts 58 on a beam 11.

In the operation of a mill equipped with my steadier, under manual control, for the purpose of explanation only, the operator is preferably stationed in a position where he can view the complete operation. With the apparatus in an operative position as shown in the drawings, a rotating mandrel bar 12 supports an advancing tube 13 thereon. During this piercing operation, for ex ample, the horizontal and rotational forces exerted on the bar tend to bend the bar along it horizontal axis and to cause it to rotate in an eccentric movement. As explained hereinabove, the bar is substantially completely confined and eccentric rotation or whipping is restricted by steadier head 36 co-operating with U-shaped base 25 or with guide means 16 and 19, where the latter are spaced closely adjacent the steadier.

After the piercing has been completed, cover 20 on guide 19 is retracted by actuating hydraulic motor 22. Steadier head 36 is retracted to an out-of-the-way position, as shown in chain lines in FIG. 3, by actuating hydraulic motor 53 and thereby advancing its piston 52. Bar 12 is retracted and kickout mechanism 14 is actuated to discharge tube 13 transversely, for example, to a cooling table, not shown. Thereafter, the apparatus is returned to the positions shown in the drawings and the above-described operation is repeated.

The described mechanism embodies a relatively simple structure which is low in maintenance cost and has operated with no bar failure attributable to malfunctioning of my steadier. The mechanism is accessible for making rapid size changes. Being simple in design, many of the parts can be cast to size with little machining required. My apparatus may be used in reeling, rotary rolling, elongating and high-mill operations associated with the seamless tube production process. Obviously, more than one steadier may be aligned on a mill outlet table.

Although I have disclosed herein the preferred apparatus and operation of my invention, I intend to cover as well any change or modification therein which may be made without departing from the spirit and scope of the invention.

I claim:

1. A steadier for a seamless-tube mill having a mandrel bar adapted to support tube shells as they move axially comprising a base having a standard thereon, a portion of said base extending under the path of the shells, a bearing supported on said standard, having a horizontal axis, a shaft journaled in said bearing and extending over said path, a crank on said shaft, a steadier head on Said crank having an axis substantially perpendicular to siad path when in operating position and thereby cooperating with and confining said bar or a shell thereon, means for turning said shaft to rotate said head from an out-of-the-way position to a position in which it confines said bar or shell and steadies it, said head also including a housing and a yoke shaped block removably disposed therein to cooperate with an to confine said bar or shell.

2. A steadier as defined in claim 1 including a guide means co-operable with said bar or shell, extending under said path and spaced from said base along said path.

3. A steadier as defined in claim 1 in which said housing has a yoke-shaped retaining flange at one end thereof and a yoke-shaped block removably mounted in said housing adjacent said flange, said block co-operating with and confining said bar or shell from above and on either side thereof and said base portion extending under the path of said bar or shell co-operating with and confining said bar or shell from below.

References Cited UNITED STATES PATENTS 2,535,949 12/1950 Offutt 7297 3,021,736 2/1962 Schuetz 7297 3,101,015 8/1963 Schuetz 72-97 RICHARD J. HERBST, Primary Examiner M. J. KEENAN, Assistant Examiner US. Cl. X.R. 7297 

